Road-cleaning vehicle



June 3, 1969 w. MAASBERG ROAD-CLEANING VEHICLE Filed March 1e, 1967 Sheet .o e E, m. "w

g Maasberg Inventor.

ma ../w o W By R05 l WLAttorney -June 3, 1969 w. MMSBERG, 3,447,18

ROAD CLEANING I CLE Filed March le, 1961'- sheet 2- of 2 Wolfgang Maasbrg Inventor.

Byv l w Attorney United States Patent O W 8, Int. Cl. A471 I l 29, 7/00; E01h I /08 U.S. Cl. 15-320 11 Claims ABSTRACT OF THE DISCLOSURE A road-cleaning vehicle with an array of nozzles for directing high-pressure jets of water against a ground surface transversely to the direction of movement of the vehicle and a suction head having a longitudinally extending slot parallel to the nozzle array and opening close to the ground surface forwardly of the nozzles and under subatmospheric pressure for drawing the entrained particles and the liquid upwardly from the ground surface; the suction head is connected in series with a settling (sedimenting) tank while the nozzle array trains its jets upon the ground surface directly beneath the mouth of the suction head. An air curtain is provided forwardly of the suction head and is partly formed thereby so as to form a barrier to the -passage of liquid beyond the mouth of the suction head as the vehicle moves along the road surface and the liquid jets are trained in this direction.

Specification The present invention relates to a road-cleaning vehicle of the type in which a sheet-like spray of water or other cleaning liquid is directed across a pathrtransverse to the direction of movement of the vehicle and downwardly against the road surface to be cleaned, and at least part of the water is collected by means forwardly of the spray device.

In U.S. Patent No. 3,151,348, issued Oct. 6, 1964, and entitled Device for Cleaning Roadways and Similar Surfaces, there is described a road-cleaning vehicle wherein a pump or the like driven from the vehicle engine or auxiliary means, forces a cleaning fluid, usually water, through a nozzle means in the form of a generally horizontal manifold with an array of spray nozzles longitudinally spaced therealong while a collector means in the form of a trough is disposed forwardlyof the nozzle so as to catch reflected water spray from the roadway surface being treated. The trough or collector means can have one end relatively close to the nozzle tube while another end is spaced therefrom to a greater extent, the nozzles being trained at an angle of attack of about 25- 45 toward the ground. The pump or some other circulating device carries the collected liquid laden with dirt from the ground surface, to means for purifying this intercepted water prior to its return to the source.

The present application has as its principal object the improvement of road-cleaning vehicles of that general type and of such character that at least part of the water impinging upon the road surface is collected and purified for reuse.

Another object of this invention is to provide a roadcleaning system which will operate efficiently with higher liquid pressures than has been possible heretofore and is ICC suitable for picking up relatively heavy objects and materials without mechanical means such as brushes or the like.

A further object of this invention is to provide a surface-clearing vehicle particularly suitable forthe removal of road-surface detritus of the type generally characterizing bituminous and concrete road surfaces subjected to weathering, mechanical breakdown and dislocation, as well as road subsurfaces or newly laid road beds before the application of a surfacing layer.

These objects and others which will become apparent hereinafter are attained, in accordance with the present invention, in a motor vehicle adapted to travel over the roadbed or surface to be cleared and having, in addition to a high-pressure pump, a water tank supplying this pump, and a recovery or collection system for taking up the y detritus and other waste entrained by the water, an improved nozzle assembly and collecting arrangement wherein rearwardly of at least one nozzle and forwardly of another nozzle assembly, directing jets of water against the surface at an acute angle thereto in the direction of advance of the vehicle, a suction hood is maintained at reduced pressure and with an outlet close to the ground surface for drawing the liquid impinging upon this snrface and deposited therein into the hood for purification and reuse as indicated earlier. The suction hood, according to the invention, is connected to a settling tank or other sedimentation system capable of removing heavy particles from the recovered liquid. A particularly important feature of this invention resides in the configuration of the nozzle means and the suction hood, the latter having an apron extending generally across the nozzle means and terminating close to the ground surface while the nozzles themselves are directed to impinge upon the ground surface beneath this apron and forwardly thereof in the direction of advance of the vehicle, the hood Ybeing formed with an intake slot along the swath swept by the vehicle. One side of this intake slot is dened by the a-pron which, lmoreover, constitutes the rearward edge of the slot in the direction or advance of the vehicle. The forward edge of each longitudinal slot is disposed at a greater distance from the road surface than this rearward edge so that the mouth of each hood or the intake slot lies in a plane inclined to the road surface at an angle such that its intersection with the road surface is directly below the nozzle assembly.

According to a further feature of this invention, forwardly of one or both suction hoods, an air-nozzle means is provided to direct the stream generally rearwardly and thereby for-m an air curtain tending to deect the liquid impinging on the road surface below the intake slot upwardly into the hood. Advantageously, the blower means for this air-curtain arrangement also constitutes the reduced pressure means for the suction hoods. At least one of these hoods has an intake slot whose longitudinal edges are constituted as described above and run generally parallel to the array of nozzles and transverse to the direction of movement of the vehicle, the ends of this slot being generally rounded. Moreover, the hood itself may be substantially funnel-shaped and can converge to a circularsection duct communicating with the settling tank. The air curtain itself may be formed by a slot-type nozzle extending continuously along the forward edge of the intake slot and formed by a forward apron or wall of the hood spaced from the outer apron or wall so that the forward side of the suction hood is constituted as a hollow double wall forming a narrow duct for discharging a sheet of air in the manner described. At least two nozzles constitute the nozzle means or array, these nozzles being disposed with a longitudinal spacing equivalent to the spacing between the rounded ends of the intake slot; these nozzles, moreover, are adjustable and so oriented that the jets are directed toward one another or converge in the direction of movement of the vehicle and substantially in the longitudinal median plane of the intake slot. A further nozzle may be disposed in this plane and can have a discharge angle so dimensioned with respect to the discharge angles of the other nozzles as to overlap the spray cones of the nozzles at least directly below the apron of the intake hood.

' Still another feature of this invention resides in the provision of at least two suction hoods longitudinally spaced apart along the vehicle chassis in the direction of movement thereof, each of these suction hoods having a respective nozzle assembly directing a downward and forward spray of liquid beneath the rearward edge of the intake slots. Furthermore, ahead of at least the more forward suction hood, there is provided a nozzle assembly whose jets are directed forwardly and have round orifices; by contrast, the nozzle means rearwardly of the intake hoods and adapted to direct their respective sprays beneath the intake slots, should have slot-like orifices to form the impinging stream as a sheet of water. A cover or shield is disposed above and in advance of the foremost nozzle assembly to protect the latter, although it is also possible to provide this nozzle assembly with a collecting trough of the type set forth in the commonly assigned U.S. Patent No. 3,151,348 mentioned above.

The above and other objects, features and advantages of this invention will become more readily apparent from the following description, reference being made to the accompanying drawing in which: i

FIG. l is a side-elevational view of a road-cleaning vehicle according to this invention, portions of the system being illustrated diagrammatically and other parts being broken away;

FIG. 2 is a detail cross-sectional view taken generally along the line II-II of FIG. l; and

FIG. 3 is a cross-sectional view taken along the line III-III of FIG. l.

In FIG. l, there is shown a road-cleaning vehicle in the form of a truck 100 adapted to negotiate a road surface represented at 1. When reference is made herein to a road surface, it will be understood that it is intended to designate'iinished or paved road surfaces to be cleared of dirt and other relatively light materials or a base or subsurface adapted to be covered by a paving layer which is to be freed of gravel and other relatively massive detritus. Of special importance is the clearing of a concrete subsurface from loose materials prior to the application of a finishing layer of concrete or of blacktop, macadam or other bituminous surfacing materials thereto. The vehicle 100 comprises a chassis 4, supported on the wheels 5, and driven by an engine (not shown) contained in the engine housing 2 forwardly of the operators cab 3. The back of the truck, behind the cab 3, is enclosed within a housing or truck body 7 and supports a clear-water tank 20 connected with a high-pressure pump 14 and drawing water from a settling tank 22 via a line 21 provided with a lter 23. The settling tank 22 is formed with a standpipe 24 which opens into a plenum chamber 25 above the level 26 of the liquid in the settling tank. At the base of this tank, the sludge or other detritus 27 settles from the liquid and is collected for removal via the door 28 at the rear end of the vehicle 100. A reduced pressure or suction is maintained in the plenum chamber 25 by a suction-blower means 29 which is here represented as a conventional high-velocity centrifugal blower whose intake side 29: is connected with the plenum 25 and whose outlet 29o delivers high-pressure air to an air nozzle described below to form an air curtain.

According to an important feature of this invention, the road-cleaning means includes an array 6 of highpressure nozzles 6' extending transverse to the direction of movement of the vehicle (arrow A) rearwardly of a suction hood 8 whose mouth or slot 8 is elongated and generally parallel to the nozzle array 6. The nozzle array 6 is supplied with high-pressure water from a pipeline 30 and a control valve 31 connected with the highpressure pump 14. The latter can be driven by the engine of the vehicle 100 or by a prime mover carried on the chassis 4 as described and illustrated in the aforementioned patent. The suction hood 8 is generally tlattened toward its mouth 8' so 'as to be generally funnelshaped and to converge upwardly toward a suction duct 32 connected with the standpipe 24. The hood 8, moreover, has an apron 33 extending downwardly in front of the nozzle array 6 to terminate just above the road surface 1 in an edge 10 below the horizontal plane P of the nozzles 6. The nozzles 6 yare oriented downwardly so that their sprays 6" are directed below the edge 10' against the ground surface 1.

The nozzles 6', moreover, have generally slot-shaped orices so that the angular spread a in the median plane P of the spray is greater than the spray angle in the vertical plane. The median plane P of the orices and the jets 6 is so chosen in connection with the spray angle ithat the upper edge of the jet just passes the lower edge 10 without interception thereby while the lower edge of the spray impinges upon the ground surface directly below this edge 10. The reflected water, carrying the detritus remaining on the surface as the jets 6" sweep thereover, is deflected upwardly and entrained by the retlected water spray so as to be drawn through the mouth 8 of the suction hood 8 and induced at high velocity to flow through the duct 32 and the standpipe 24 into the settling tank 22.

In the settling tank, the detritus 27 sediments from the liquid stream so that the relatively clear liquid above the sludge layer can be drawn to the lter 23 into the clean water tank 20 and thence pumped through the nozzles 6 in continued circulation. The spray angles u are so dimensioned that the spray cones overlap just below the edge 10 (see FIG. 2).

The rear wall 34 of the suction hood 8 is paralleled by an outer wall 35 forming a nozzle 9' parallel to the edge 11 and trained upon the road surface 1 directly below this edge. Thus the air jet delivered by this nozzle 9 is directed rearwardly of the direction of vehicle travel and rearwardly of the direction of the water jets 6 so as to form an air curtain represented by arrow 36. The major part of the air ilow of this curtain is deflected upwardly through the nozzle 8 so as to form a wall for stationary water particles and the detritus loosed thereby and augment the ow of fluid upwardly through the hood 8 to ensure entrainment even of relatively heavy particles therethrough. The mouth 8 of the suction hood 8 and thus the edges 10 and 11 lie in a plane P which intersects the ground plane 1 just below the nozzle array 6, this plane being divergent from the ground surface in the direction of movement of the vehicle (arrow A). The air for this air curtain or at air nozzle is delivered via a conduit 37 from the output side 29o of the blower 29. The suction ow of air through the hood 8 is induced at the intake side 29i of the same blower.

The edge 11 is, therefore, disposed at a level above that of edge 10, preferably by an amount equal substantially to the distance between the ground level and this edge. The edges 10 and 11 are, moreover, connected by rounded end portions 12 which also merge with the wall 35 of the air-curtain discharge slot 13 of nozzle 9. It has been found, moreover, that it is desirable to have the suction trough 8 inclined generally to the ground surface 1 so as to diverge upwardly therefrom in the direction of movement of the vehicle 100. While three nozzles 6 are illustrated in FIG. 2, it will be apparent that any number of such nozzles may constitute the nozzle array 6 although it is important that the spread 6" overlap as indicated above. It is highly desirable to provide at least two outer spray nozzles at the rightand left-hand ends of the array respectively such that the outer limiting portions of each spray jet of these end nozzles are bounded by the ends 12 of the mouth 8 of the suction head. At least one and possibly more intermediate nozzles 6 are provided in spaced relationship between the end nozzles.

According to an important aspect of this invention, forwardly of the head I8 and nozzle array 6 of the vehicle 100, there is provided a further suction head 58 whose cylindrical duct 59 connects this head with the standpipe 24 and thus maintains the suction head under reduced (i.e., subatmospheric pressure). The suction head 58 is, moreover, generally funnel-shaped (FIG. 3) and inclined upwardly and forwardly from the -gr-ound surface 1. Furthermore, in a manner analogous to the suction head 8, the suction head 58 is provided with a mouth 58 bordered by a pair of longitudinally extending edges 60 and 61 which run transversely of the direction of movement A 0f the vehicle. Again, rounded edges 62 are provided at each end `of the slot 58 which cooperates with a nozzle array 58 whose nozzles 56' are disposed at a distance from one another equal substantially to the length of the slot 58. The nozzles 56 are thus disposed practically at the ends of the slot 58 and are directed inwardly so that their fiattened spray cones of angle a overlap beneath the edge 60 of this slot. These nozzles are, moreover, oriented in a plane p' Isuch that the spray of these nozzles, which impinges upon the ground surface in the region directly below the edges 60 and 61 and is reflected upwardly into the suction head 58. The slot 58 is, moreover, of a smaller length than the slot 8 of hood 8. Additional nozzles 56 can, of course, be disposed along the array 56, as illustrated in FIG. 2. The array 56 is supplied with high-pressure liquid by a line 40 and a Valve 41 communicating with a high-pressure pump 14. It will thus be apparent that a substantial portion of the water impinging upon the ground surface 1 from the nozzles 56 is reflected and drawn upwardly through the suction head 58 along with any detritus intercepted by the water. From the head 58, this mixture of air, liquid spray and waste material fiows through the standpipe 24 into the settling tank in which the solid materials sediment or settle from the liquid.

Forwardly of the suction head 58, there is provided a further array of nozzles 76 with nozzles 76', adapted to direct conical sprays 76" downwardly against the road surface. This array 76 is received within an inverted trough or shield 15 to protect the nozzle assembly from contact with large-size particles upon sweeping them aside. The nozzle array 76 advantageously serves to initially loosen the detritus on the ground surface and, like nozzle 6 and 56, may train jets of washing liquid which are fed to the nozzles at a pressure on the order of hundreds of atmospheres. The nozzles 6', 56 and 76 lare swivellably mounted upon respective supports such as that shown yat 56a and have spray heads 56b (FIG. 3) provided with orifices of the proper shape. For the generally fiat and sheet-like sprays generated by nozzles 6' and 56', these orifices are substantially slot-like whereas the orifices of nozzles 76 are of circular section. A pipe 77 connects the nozzle area 76 with the pump via lines 40 and 41.

The invention described and illustrated is believed to admit of many modifications within the ability of persons skilled in the art, all such modifications being considered within the spirit and scope of the appended claims.

What is claimed is:

1. A roadcleaning vehicle adapted to traverse a ground surface, comprising in combination with a vehicle chassls:

a first suction head mounted on said chassis and having an elongated mouth open close to said ground surface and extending transversely of the direction of movement of the vehicle;

a first nozzle array mounted on said chassis rearwardly of said first suction head for directing a plunality of liquid jets against said ground surface directly below said mouth;

high-pressure pump means connected with said first Iarray for supplying same with a cleaning liquid under pressure;

a settling tank communicating with said first suction head for receiving liquid-entrained material drawn in through said first head from said ground surface for separating solid matter from the liquid;

suction means for applying a reduced pressure to said first suction head to cause the induction therethrough of liquid-entrained solid particles;

a second suction head mounted on said chassis forwardly of said first suction head in the direction of movement of said vehicle and communicating with said settling tank; and

a second array of nozzles extending parallel to said second suction head and having a plurality of nozzles trained upon said ground surface directly below said second suction head, said second suction head having a mouth of a length less than that of the mouth of said first suction head and lying in a plane inclined to said ground surface and diverging therefrom in the direction of movement of said vehicle.

2. A road-cleaning vehicle as defined in claim 1, further comprising .air-nozzle means forwardly of said rst suction head and extending along said mouth of said first suction head for directing an air curtain against said surface to prevent the passage of liquid from said jets of said first array Ibeyond said mouth of said first suction head.

3. A road-cleaning vehicle as defined in claim 2 wherein said first suction head is a generally fiat funnel-shaped body ldepending from said chassis and open downwardly against said surface at said mouth of said first suction head, a forward wall of said body in the direction of movement of said vehicle being generally hollow and for-ming said air-nozzle means.

4. A road-cleaning vehicle as defined in claim 2 wherein said suction means is a high-velocity blower having an intake side communicating with said first suction head and an outlet side communicating with an air-nozzle means.

5. A road-cleaning vehicle as defined in claim 1 wherein said mouth of said first suction head is bounded by a relatively forward edge and a relatively rearward edge, said relatively forward edge lying at a level above said rearward edge in respect to said ground surface.

6. A road-cleaning vehicle as defined in claim 1 wherein said first suction head is inclined upwardly away from said ground surface in the direction of movement of said rvehicle.

7. A road-cleaning vehicle as defined in claim 1 wherein said mouth of said first suction head is formed at its extremities with rounded end portions.

8. A road-cleaning vehicle as defined in claim 1 wherein the nozzles of said first array have generally fiat sprays which overlap below said mouth and are so trained against said ground surface that all of the jets therefrom impinge upon said surface forwardly of the rearward edge of said mouth of said first suction head and rearwardly of the forward edge of said mouth of said first suction head.

9. A road-cleaning vehicle as defined in claim 1 wherein at least two end nozzles are provided in said first array at opposite extremities of said mouth of said first suction head; said end nozzles being trained inwardly and downwardly in the direction of movement of said vehicle.

7 8 10. A road-cleaning vehicle as dened in claim 1, fur- References Cited ther comprising an auxiliary nozzle array disposed for UNITED STATES PATENTS Wardly of at least one of said suction heads and ex tending generally parallel thereto proximal to the mouth 2684558 7/1954 Harris et a1' a of 5 aise; Wardly and forwardly against said surfcae for loosening 3221358 12/1965 Dcksong -S- MS X detritus thereon. I T--- 11. A road-cleaning vehicle as defined in claim 10, fur- ROBERT W- MICHELL, Primary Examiner. ther comprising a shield enclosing and extending for- Us` CL X R wardly of said array. 15-340, 346 

